1. Field of the Invention
The invention relates to an environmentally friendly gas conversion process which produces and disposes of ammonia in the process. More particularly, the invention relates to a gas conversion process which includes (i) synthesis gas generation, (ii) hydrocarbon synthesis and (iii) catalyst rejuvenation which produces ammonia containing gas, from which the ammonia is removed with water and disposed of by using the hydrocarbon gas feed to the synthesis gas generator to strip it out of the water and into the generator, where it is consumed.
2. Background of the Invention
Hydrocarbon synthesis (HCS) processes are well known and include fixed bed, fluid bed and slurry type processes in which a synthesis gas (syngas) comprising a mixture of H.sub.2 and CO is reacted in the presence of a suitable Fischer-Tropsch type of hydrocarbon synthesis catalyst at conditions effective to form hydrocarbons, and preferably C.sub.5+ hydrocarbons which are solid at standard room temperature conditions of temperature and pressure. The syngas is produced by reacting a low molecular weight hydrocarbon gas with oxygen and steam, via well known processes which include partial oxidation with or without a catalyst, catalytic steam reforming and combination thereof, using a fixed or fluid catalyst bed. Syngas made from hydrocarbon gas which contains nitrogen (i.e., natural gas) or nitrogen containing compounds (i.e., the hydrocarbon gas is derived from a resid, coal, shale, coke, tar sands, etc.) invariably contains nitrogen species (e.g., HCN and NH.sub.3 which deactivate the HCS catalyst. This deactivation may be reversed and catalytic activity restored (rejuvenated) by contacting the deactivated catalyst with hydrogen or a hydrogen containing gas (rejuvenating gas) as is disclosed, for example, in U.S. Pat. No. 5,260,239. The rejuvenation produces ammonia which must be removed from the gas and disposed. U.S. Pat. Nos. 4,189,307; 4,769,224 and 5,068,254 and European patent publications EP 0 661 372 A and EP 0 661 375 A disclose methods for removing ammonia and cyanide from syngas, including recycle of ammonia containing gas and water back into the syngas generator, but do not address a gas conversion process which includes removal and disposal of ammonia from an HCS catalyst rejuvenation offgas.